Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Light distribution control method, light distribution control device, and greenhouse using the same

Light distribution control method, light distribution control device, and greenhouse using the same description/claims

1. Field of the Invention

The present invention relates to a passive daylighting technology or a technology for controlling a flux of an artificial light source without using a driving means.

2. Description of the Related Art

A venetian blind disclosed in JP 2002-081275A by the applicant of the present invention provides a structure wherein each of transparent slats are divided into two portions, outdoor side and indoor side, and a number of ridges each of which has substantially circular cross section are arrayed sufficiently/substantially close to each other in the direction perpendicular to the longitudinal axis of the slat on the upper surface of the outdoor side of the slat. The sunlight reflected on this surface is diffused substantially symmetrically by the ridges with respect to an axis parallel to a longitudinal direction of each of the ridges, then strikes the lower surface of the indoor side of the slat just above, and is transmitted being diffused by the ridges given in the manner similar to the above in the longitudinal direction of the slat substantially symmetrically with respect to an axis parallel to longitudinal direction of the stat, thereby diffused widely into a room.

JP 2002-081275A also discloses a light distribution control device for bringing in light to a shaded area or part by using diffused light passing through a surface of a plate or film structure in which the same ridges are arrayed, or for reducing glare by uniformly diffusing a flux of a lamp.

However, the array of the ridges required for such blind and light distribution control device demands a high level of manufacturing technology, so that it is not easy to stably realize the shape and the function satisfied in stable basis. Therefore, the symmetry of diffused rays with respect to a light incident at a large azimuth angle is not sufficient. In a case of the use of such diffused light passing through the surface of the structure, a large portion of light is lost due to the reflection on the surface of the structure. This results in leaving room for improvement of energy use efficiency.

The present invention has made to solve the above-mentioned problems, and an object of the present invention is to provide a light distribution control method and device/equipment capable of efficiently utilizing diffused light with ideas in design and use of such structure, without demanding improvement of the manufacturing technology close to which is almost hitting the limit of current technology level.

Another object of the present invention is to provide a greenhouse using such a light distribution control device/equipment.

The light distribution control method in the present invention employs a plate or film like structure which is at least either transparent or reflective, and has a number of ridges arrayed parallel and sufficiently/substantially close to each other on at least one of the faces of the structure wherein each of the ridges has a substantially circular cross section orthogonal to the longitudinal direction of the ridge, so that the light incident to the practically specular surfaces of such a number of ridges are diffused in a conical plane or half conical plane which has center axis with a line passing through the incident point and parallel to the ridges.

The “practically specular surface” can be defined as follows.

It has been known that, when the size of a rugged spot/an unevenness of a predetermined surface of a structure is sufficiently smaller than a wavelength of light, the light incident on the surface has specular reflection, while, the size of the rugged spot/such an unevenness is equal to or larger than the wavelength of the light, such light has irregular/scattered reflection (diffused reflection). A surface which causes specular reflection is generally called a “specular surface”

When most of the subject surface is a “specular surface”, or comprises portions of “specular surfaces” distributed substantially uniformly, and the ratio of the aggregated area of the specular surface portions to the area of the predetermined portion of the surface (referred to as “Specular Ratio”) is considered within an appropriate range in view of the use of the subject surface, the subject surface is defined as a “practically specular surface”. For example, in view of the function demanded, a mirror is required to have specular reflection with most of incident light, and thus the Specular Ratio may be about equal to or larger than 0.9.

The light distribution control device in respect to the present invention comprises a plurality of structures, each of which is formed in a plate like shape and a film like shape with at least one of optical transparency and optical reflectivity, and includes a number of ridges which are arrayed in parallel on at least one of the surfaces of the each structure and placed sufficiently/substantially close to each other, each of the ridges having its cross section orthogonal to the longitudinal direction of the ridges, formed in a portion of a substantial circle, and the surface practically specular, the structures being arrayed such that the ridges are parallel to each other and the corresponding surfaces of the adjacent two of the structures are in parallel and apart from each other at a predetermined distance, wherein light diffused in one of a circular conical plane-like and a semi-circular conical plane like having the center axis with a line parallel to the ridges is transmitted in a direction for light distribution when light is incident on the ridges of each of the structures.

It is preferable to have the plurality of ridges formed on each of the surfaces of the each structure.

Further, each of the structures may have one of a long and thin plate structure or a long and thin film structure, or a number of ridges may be formed along the direction crossing the longitudinal direction of each of the structures. In this case, each of the structures may have a bent shape or a V-shape in its cross section orthogonal to the longitudinal direction thereof.

The light distribution control device preferably further includes an adjusting mechanism for varying the angle of the each structure relative to the arraying direction of the plurality of structures.

The light distribution control device of the present invention may be installed at the windows, through which outside light enters and the plurality of structures may be arrayed along a surface of the windows to redirect light diffused by the ridges of each of the structures into a room, at a place which gets light from outside and is located above an shaded area by a building to redirect the outside light diffused by the ridges of each of the structures into the area which would be shaded by the building or in a greenhouse at least either on the ceiling portion, on the wall portion or in the vicinity of either one of those to bring in diffused light by the ridges of each of the structures to the interior space of the greenhouse.

The greenhouse in respect to the present invention is provided by having the above mentioned light distribution control device at least either on the ceiling or the wall or in the vicinity of either one of those.

Further, at least either the ceiling portion or the wall portion can be made with light distribution panels each of which comprises the light distribution control device held between double structured transparent plates.

• Provisional Patent
• Utility Patent

• What Is a Patent?
• What Is a Trademark or Servicemark?
• What Is a Copyright?
• Patent Laws